A cobposatiost



rarefied Feb. 14, 1928.

UNITED STATES PATENT OFFICE.

IVAN GUBELMANN, HENRY J. WEILAND, AND OTTO STALIQMANN OF SOUTH MIL- WAUKEE, WISCONSIN, ASSIGNORS TO THE NEWPORT COMPANY. OF CARROLLVILLE. WISCONSIN, A CORPORATION OF DELAWARE.

3'-5-DINITRO-4'-HYDROXY-ORTHO-BENZOYL-BENZOIC ACID AND PROCESS 01 MAKING THE N0 Drawing Application filed November;

,Thisiuvention relates to Q -5'-dinitro-'1l,- liydroxy-orlhb-henzoyl-heiizoie acid and a process of making the same.

We have discovered that 4'-hydroxy-ortho-heuzoyl-benzoie acid can be uitratcd with suitable nitrating agents, such as nitrir acid, a mixture of sulphuric and nitric, acids,uilrates and the like. to the 3 5'dinit.ro-4-hydroxy orth0-henzoyl-be'nzoic acid, having mostp'robably the following structure:

The nitration can be carried out at various temperatures, in various solvents and in various strengthsof acids. The nitration proceeds intu'o steps, the first step giring the iuono-nit-i'o derivative, which has already been described in our ell-pending application;Serial No. 119,247, filed June 1926. The mono-nilro derivative, procl u-vd either according tothe prcscul' pros-ens, or according to. the rroccss in the above rcferred to application, is upon further addition of nitric acid or i-ilhcunitrating agent, transfori'ned into the diuilro derivative. The genera reaction can most SAME.

29. 1926. Serial No. 151,591.

prohahly he exprcssml by the following chemical equations:

The 3'-5-dinitro 1'-hydroxy o-benzoylhenzoic acid is a pale yellow crystalline -powder, somewhat soluble in cold water and fairly soluble in hot \ralcr. ll easily mluhle in alcohol, but is almost. insuiuhhin d'zhue mineral acid. It dissolves readily in alcohol, a melting point of 198200 C. can be obtained on the purified compound.

lVithout limiting our invention to any particular procedure, the following example, in which parts by weight are given, illustrates the application of our invention in the preferred form.

243 parts of para -hydroXy-ortho-benzoylbenzoic acid are dissolved in 484 parts of sulphuric mono-hydrate at a ten'iperaturc of about 25 C. This solution is cooled to 18 C. and 800 parts of a mixture analyzing 17% nitric acid and 87% sulphuric acid is run in slowly at that temperature. After all the mixed acid has been run in, the temperature of 18 C. is maintained for an additional hour. The nitration mass is then diluted by pouring it into a mixture prepared from 1000 parts of ice and 2000 parts of water and stirred until homogeneous. The precipitated dinitro body is then filtered oil and Washed on a filter with about 1000 parts of cold water until free of mineral acid. The washed product is then dried at 100 C. The yield is 316 parts, corresponding to 95% of theory, having a melting point on the crude of 193195 C. Upon recrystallization of the crude product from diluted alcohol, the melting oint of the purified dinitro-hydroxy-orthoenzoyl-benzoic acid is 198200 C.

It will be understood that instead of starting with the para-hydroxy-orth0-benzoylbenzoic acid, the starting material may be i the inonouiitro body, 3-nitro-4-hydroxyortho-benzoyl-benzoie acid, such as described in the application referred to.

2. The process of preparing 3-5-dinit-ro- 4' hydroxy ortho benzoyl bcnzoic acid, which comprises treating 4-hydroxyorthobenzoyl-benzoic acid dissolved in sulphuric .acid monohydrate with a nitrating mixture analyzing approximately l'Z per cent nitric acid and 87 per cent sulphuric acid at a relatively low temperature, diluting the nitration mass to precipitate the dinitro body and isolating said dinitro body.

In testimony whereof we have hereunto subscribed our names.

l\':\I\' ll' BlCL-MANN. lllCNJY J. \VEILAND. OTTO S'IALLMANN. 

